package org.apache.hadoop.io;

import java.io.*;

/**
 * A WritableComparable for ints.
 */
public class IntWritable implements WritableComparable {
  private int value;

  public IntWritable() {
  }

  public IntWritable(int value) {
    set(value);
  }

  /**
   * Set the value of this IntWritable.
   */
  public void set(int value) {
    this.value = value;
  }

  /**
   * Return the value of this IntWritable.
   */
  public int get() {
    return value;
  }

  public void readFields(DataInput in) throws IOException {
    value = in.readInt();
  }

  public void write(DataOutput out) throws IOException {
    out.writeInt(value);
  }

  /**
   * Returns true iff <code>o</code> is a IntWritable with the same value.
   */
  public boolean equals(Object o) {
    if (!(o instanceof IntWritable))
      return false;
    IntWritable other = (IntWritable) o;
    return this.value == other.value;
  }

  public int hashCode() {
    return (int) value;
  }

  /**
   * Compares two IntWritables.
   */
  public int compareTo(Object o) {
    int thisValue = this.value;
    int thatValue = ((IntWritable) o).value;
    return thisValue - thatValue;
  }

  public String toString() {
    return Integer.toString(value);
  }

  /**
   * A Comparator optimized for IntWritable.
   */
  public static class Comparator extends WritableComparator {
    public Comparator() {
      super(IntWritable.class);
    }

    public int compare(byte[] b1, int s1, int l1,
                       byte[] b2, int s2, int l2) {
      int thisValue = readInt(b1, s1);
      int thatValue = readInt(b2, s2);
      return thisValue - thatValue;
    }
  }

  static {                                        // register this comparator
    WritableComparator.define(IntWritable.class, new Comparator());
  }
}

